铂铝涂层高温氧化的影响因素研究

Influence Factors of High Temperature Oxidation for Pt-Modified-Aluminide Bond Coatings

摘要:

研究比较沉积热障涂层和无热障涂层的镍基高温合金铂改性铝化物涂层在900，1000和1100 ℃空气中高温氧化生成的氧化铝层表面形态和断面结构。发现低铂含量涂层氧化初期热生长层(TGO)表面有放射状裂纹形成和长大，造成氧化铝的局部脱落，并在TGO与铂铝涂层界面形成空洞。涂层900 ℃循环氧化300 h后TGO内部均形成空洞。而在1100 ℃氧化时，TBC陶瓷层的存在改变了两种铂铝涂层TGO的内应力变化趋势，升高温度使TGO厚度迅速增大，涂层寿命迅速下降

Abstract:

Oxidation of EB-PVD thermal barrier coatings (TBC) deposited and undeposited on nickel base superalloy CMSX-4 with Pt content modified aluminide bond coating have been studied in air at 900, 1000 and 1100 ℃ in order to determine the influence factor of temperature, Pt content and TBC for TGO. It is found that some cracks growth due to the alumina phase transformation and aluminum oxide spallation happened on the surface of low αAl coating TGO. Some voids were formed on the interface between TGO and low aAl bond coating during the initial oxidation period. However, at 900 ℃ inner voids still exist after 300 h oxidation. Thermally grown oxide (TGO) stress trend of samples with TBC was also different compared with that without TBC. The TBC lifetime would be rapidly decreased if the operated oxidation temperature increases